Fe-terpyridyl complex based multiple switches for application in molecular logic gates and circuits

Molecular logic gates and circuits are constructed using the optical and electrochemical addressable-reversible-multiple switching event of the Fe(H)-4'-pyridyl terpyridyl complex (1) using multiple analytes. The process involves oxidation reduction of Fe2+ as well as successive quaternization-dequaternization of the free pendant pyridyl group monitored optically. The whole switching process could also be visualized by the naked eye as colour changes upon switching are quite apparent and instant.